1. Influences of silicon doping in quantum dot layers on optical characteristics of InAs/GaAs quantum dot infrared photodetector
- Author
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Cheng-Shuan Tsai, Cheng-Chung Chi, Meng-Chyi Wu, Jim-Yong Chi, Chun-Yuan Huang, Shu-Ting Chou, Shih-Yen Lin, Tzu-Min Ou, and Bang-Yu Hsu
- Subjects
Photoluminescence ,Materials science ,Condensed matter physics ,Silicon ,business.industry ,Doping ,Binding energy ,Metals and Alloys ,chemistry.chemical_element ,Surfaces and Interfaces ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,chemistry ,Quantum dot laser ,Quantum dot ,Materials Chemistry ,Optoelectronics ,business ,Molecular beam epitaxy ,Wetting layer - Abstract
We have investigated the effects of silicon doping concentration within thirty-period self-assembled quantum dot (QD) layers on quantum dot infrared photodetectors (QDIPs). The lens-shaped quantum dots with the dot density of 1 × 10 11 cm − 2 were observed by atomic force microscope (AFM). From the high ratio of photoluminescence (PL) peak intensities from dot layer to that from wetting layer, we have concluded that high dot density caused the short diffusion length for carriers to be easily captured by QDs. Moreover, the Si-doped samples exhibited the multi-state transitions within the quantum dots, which were different to the single level transition of undoped sample. Besides, the dominant PL peaks of Si-doped samples were red-shifted by about 25 meV compared to that of the undoped sample. It should result from the dopant-induced lowest transition state and therefore, the energy difference should be equal to the binding energy of Si in InAs QDs.
- Published
- 2007
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